Methods: We use positron emission tomography (PET) and functional magnetic resonance imaging (fMRI)to map language and memory neuroimaging in patients with temporal lobe epilepsy to perform non- invasive evaluation of functional cortex, and study the effect of epilepsy on cognitive anatomy in children and adults with seizures. This information is crucial as well for surgical planning in patients with intractable epilepsy.Our studies in both normal volunteers and patients with uncontrolled seizures have shown that imaging evaluation compares well with more invasive procdures such as electrostimulation mapping and the intracarotid sodium amytal test. We also evaluate the effect of seizures on the development of functional cognitive anatomy. Recent findings: We used fMRI to compare activation on a verbal fluency task in children and adults. In both groups, left inferior frontal cortex and left middle frontal gyrus (dorsolateral prefrontal cortex)were activated. Children had, on average, 60% more activation than adults. The degree of laterality was less in children than for adults in IFG and MFG. The greater activation found in children may reflect developmental plasticity for the ongoing organization of neural networks which underlie language capacity. We also used PET to study word rhyming and pseudoword rhyming, which activated the same brain regions, suggesting conjoint neural networks for phonological processing of words and pseudowords. However, pseudoword rhyming also recruited more cortical tissue in the left posterior prefrontal cortices and the left ventral occipital-temporal junction. In addition, pseudoword rhyming activated the left supramarginal gyrus which was not actively engaged in word rhyming. These results suggest that rhyming pseudowords requires extended neural systems and networks unnecessary for rhyming words. Current studies: We are using several new tasks to investigate functional reorganization in patients with epileptic foci in langauge processing regions. - Epilepsy, cognitive function, language, memory - Human Subjects